1. Field of the Invention
The present invention relates to a method for the low temperature cleaning of the atmosphere and more particularly to the rendering of the outer surface of a heat exchanger, such as a radiator of a motor vehicle, capable of catalytically converting pollutants to harmless compounds without adversely affecting the functioning of the heat exchanger.
2. Discussion of the Related Art
A review of literature relating to pollution control reveals that the general approach is to reactively clean waste streams entering the environment. If too much of one pollutant or another is detected or being discharged, the tendency had been to focus on the source of the pollutant. For the most part gaseous streams are treated to reduce the pollutants prior to entering the atmosphere.
It has been disclosed to treat atmospheric air directed into a confined space to remove undesirable components therein. However, there has been little effort to treat pollutants which are already in the environment; the environment has been left to its own self cleansing systems.
References are known which disclose proactively cleaning the environment. U.S. Pat. No. 3,738,088 discloses an air filtering assembly for cleaning pollution from the ambient air by utilizing a vehicle as in mobile cleaning device. A variety of elements are disclosed to be used in combination with a vehicle to clean the ambient air as the vehicle is driven through the environment. In particular, there is disclosed ducting to control air stream velocity and direct the air to various filter means. The filter means can include filters and electronic precipitators. Catalyzed postfilters are disclosed to be useful to treat nonparticulate or aerosol pollution such as carbon monoxide, unburned hydrocarbons, nitrous oxide and/or sulfur oxides, and the like.
Another approach is disclosed in U.S. Pat. No. 5,147,429. There is disclosed a mobile airborne air cleaning station. In particular this patent features a dirigible for collecting air. The dirigible has a plurality of different types of air cleaning devices contained therein. The air cleaning devices disclosed include wet scrubbers, filtration machines, and cyclonic spray scrubbers.
The difficulty with devices disclosed to proactively clean the atmospheric air is that they require new and additional equipment. Even the modified vehicle disclosed in U.S. Pat. No. 3,738,088 requires ducting and filters which can include catalytic filters.
Responsive to the difficulties associated with devices with proactively treating the atmosphere, the Assignee herein in U.S. patent application Ser. No. 08/410,445 filed on Mar. 24, 1995, (abandoned), U.S. patent application Ser. No. 08/682,174 filed Jul. 16, 1996 U.S. patent application Ser. No. 08/589,182 filed Jan. 19, 1996, and U.S. patent application Ser. No. 08/589,030 filed Jan. 19, 1996, each incorporated herein by reference, disclosed apparatus in related methods for treating the atmosphere by employing a moving vehicle. In preferred embodiments a portion of the cooling system (e.g. the radiator) is coated with a catalytic or adsorption composition. Additionally, a fan associated with the cooling system can operate to draw or force air into operative contact with the radiator. Pollutants contained within the air such as ozone and/or carbon monoxide are then converted to non-polluting compounds (e.g. oxygen gas and carbon dioxide).
The Assignee herein also has pending U.S. patent application Ser. No. 08/412,525 filed on Mar. 29, 1995, (abandoned), U.S. patent application Ser. No. 08/589,032 filed Jan. 19, 1996 incorporated herein by reference, which discloses devices and methods for proactively treating the atmosphere employing a stationary object such as an automobile at rest, a billboard, an air conditioning unit and alike with catalytic composition.
The application of a catalytic composition to the surface of a heat exchange device such as a radiator of a motor vehicle presents problems which can adversely affect the heat exchange properties of the device. For example, the catalytic composition can act as an insulator thereby reducing the ability the radiator to dissipate heat.
It would therefore be a significant advance in the art of reducing pollution to employ heat exchange devices for the treatment of air to remove pollutants without adversely affecting the heat exchange properties of the device. It would be of further advance in the art if this problem could be overcome in an effective and cost efficient manner.